Field of Invention
The present invention relates to a rotor assembling method for an electric turbo-charger and a rotor assembled by the same, and more particularly, to a rotor assembling method for an electric turbo-charger in which a temperature has less influences on a permanent magnet at the time of thermally inserting a rotor component and post processing is easier such as in tip clearance adjustment, and a rotor assembled by the same.
Description of Related Art
In general, a turbo-charger is a device that rotates a turbine by using pressure of exhaust gas discharged from an engine and thereafter, increases an output of the engine by supplying high-pressure air to a combustion chamber by using rotational force thereof. The turbo-charger has a problem in which a turbo-lag phenomenon occurs at low speed.
As a result, in recent years, an electric turbo-charger is applied, in which a compressor is driven by a drive motor at low speed and the compressor is driven by using the rotational force of the turbine that is rotated by the exhaust gas at high speed by driving a shaft of the turbo-charger with an electric motor.
The electric turbo-charger has an electric motor provided in a housing thereof, and in the electric motor, a rotor is installed on a shaft that connects a turbine wheel and a compressor wheel and a stator is installed in the housing thereof.
In particular, the performance or durability of the rotor depends on an interassembly method of a permanent magnet provided therein and a casing component for fixing the permanent magnet. That is, a connector, an end cap, a retention ring, and the like which are the casing components covering the permanent magnet are made of INCONEL materials, and have very high rigidity and are not easily processed.
Further, an irregular tolerance occurs on a connection surface of the shaft with the casing component due to a processing tolerance which occurs during processing and post processing is performed in order to remove the irregular tolerance. However, since INCONEL as the material of the casing component has high rigidity and precision is required for the assembly process, post processing is trouble and it is difficult to increase completeness.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.